1. Field of the Invention
The present invention relates to cosmetic compositions. In particular, it relates to cosmetic compositions intended for shaving of the skin which comprise polyorganosiloxanes.
2. The Related Art
Such shaving products can be creams or can be dispensed from a suitable package as an aerosol foam or a post-foaming gel. The present invention is particularly concerned with the latter types of products which can be dispensed from a valved container adapted to maintain the product under pressure and dispense it when desired by opening the valve.
Aerosol-foam shaving compositions are normally contained in a single-compartment dispenser with the inert volatile liquid agent as the propellant gas in accordance with conventional aerosol technology.
Post-foaming gel shaving compositions can be packaged in many types of containers which are commercially available. Where aerosol dispensers are employed, generally the gel is maintained in a package separate from the propellant by means of a conventional `bag in can` packaging system or a diaphragm inside the package driven by a propellant or a mechanical force, such as a spring. Suitable dispenser forms are described in e.g. U.S. Pat. No. 3,541,581.
The use of polyorganosiloxanes in shaving compositions is well known. Their function is to alleviate shaving rash and generally improve lubrication and softness of skin. Typical examples of shaving compositions with polyorganosiloxanes can be found in U.S. Pat. No. 4,957,732, U.S. Pat. No. 5,104,643 and WO 91/07943.
In U.S. Pat. No. 4,957,732 shaving compositions, in particular of the aerosol type, are described which include a polyorganosiloxane containing a specific acyloxyalkyl group. Improved stability, smoothness and hair-cutting benefits are claimed.
In U.S. Pat. No. 5,104,643 shaving compositions, both aerosol and gel-type products, are described which include a polyorganosiloxane containing a specific hydroxyalkyl group. Again stability, smoothness and hair-cutting benefits are claimed.
In WO 91/07943 a post-foaming shaving gel is described comprising a polysiloxane polyether copolymer. Clarity and brightness effects are claimed.
Whilst these shaving products represent a popular form of pre-shaving treatment, there is scope for improving their aesthetic and sensory properties. In particular, there is scope for improvement of the properties of these compositions with regard to the lubrication that they provide to the blade whilst shaving, the foam quality, and also the feel of the skin after the shaving process.
It is an object of this invention to improve on these, and other problems associated with the prior art compositions.